Available Samarium Cobalt Magnet Grades

Samarium Cobalt Magnetic and Physical Characteristics

Many grades of Samarium Cobalt magnets exist to support a variety of industrial applications.  The range of SmCo magnet grades typically extends from 16 MGOe to 32 MGOe.  This range allows for optimizing cost, performance, and operational temperature resistance.
There are two main types of Samarium Cobalt magnet alloy.  The older version, typically denoted as (1-5) having one Samarium atom per 5 Cobalt atoms, and the newer Samarium Cobalt magnet alloy, typically denoted as (2-17), having an atomic ratio of two Samarium atoms to 14 – 17 Cobalt atoms.  (The 14 – 17 atoms are actually comprised of a mix of transition metals, Cobalt, Copper, and Iron, where Cobalt is the most abundant.)

Samarium Cobalt (1-5):

Has an Energy Product range of 15 – 24 MGOe and can typically operate up to 250°C.  By weight this alloy will be compromised of approximately 35% Samarium and the balance being Cobalt.  Typically the more recent (2-17) Samarium Cobalt magnet alloy will be selected for new applications because of the higher Energy Densities and temperature operating points; however, the older alloy is specified on many drawings originating from the late 1970’s through the late 1990’s and oftentimes it cannot be substituted.

Samarium Cobalt (1-5)
Dura Magnet Grade	Residual Induction Br		Coercive Force Hc		Intrinsic Coercive Force Hci		Maximum Energy Product (BH)max		Max. Working Temp.*
	Range		Range		Minimum		Range
	k-Gauss	Tesla	k-Oersted	kA/m	k-Oersted	kA/m	MGOe	kJ/m3
SC-1615	7.7-8.6	0.77-0.86	7.7-8.3	613-664	15	1,194	15-18	120-143	250°C / 482°F
SC-1819	8.3-8.9	0.83-0.89	8.0-8.6	640-688	19	1,520	17-19	136-152	250°C / 482°F
SC-2019	8.7-9.3	0.87-0.93	8.3-8.9	664-712	19	1,520	19-21	136-168	250°C / 482°F
SC-2219	9.2-9.8	0.92-0.98	8.6-9.4	688-755	16	1,280	21-23	168-184	250°C / 482°F
SC-2416	9.7-10.3	0.97-1.03	9.1-9.9	728-792	16	1,280	23-25	184-200	250°C / 482°F
*The effective Maximum Operating Temperature for a Samarium Cobalt Magnet is a function of the magnet’s magnetic characteristics and the geometry of the system (the magnet and the circuit). The listing maximum operating temperature is a recommendation and infers and ideal geometry and no external demagnetizing fields. Please engage Dura to review the application before selecting a particular grade.

Samarium Cobalt (2-17):

Has an Energy Product range of 21 – 32 MGOe and typically operates up to 300°C to 350°C.  By weight, this alloy will be comprised of approximately 25% Samarium and the remainder being the Transition Metal blend comprised mostly of Cobalt.  The higher Energy Density and operating temperatures allows this magnet alloy to be a favorite choice of designers when magnetic and environmental performance is paramount.

Samarium Cobalt (2-17)
Dura Magnet Grade	Residual Induction Br		Coercive Force Hc		Intrinsic Coercive Force Hci		Maximum Energy Product (BH)max		Max. Working Temp.*
	Range		Range		Minimum		Range
	k-Gauss	Tesla	k-Oersted	kA/m	k-Oersted	kA/m	MGOe	kJ/m3
SC-2228	9.4-10.0	0.94-1.0	9.0-9.8	720-784	28	2,240	21-23	168-184	350°C / 662°F
SC-2428	10.0-10.6	1.0-1.06	9.2-10.0	736-800	28	2,240	23-25	192-208	350°C / 662°F
SC-2618	10.5-10.9	1.03-1.09	9.3-10.3	744-824	18	1,440	25-27	200-216	300°C / 572°F
SC-2826	10.7-11.3	1.07-1.13	9.4-10.6	752-848	26	2,080	27 - 29	216-232	300°C / 572°F
SC-3018	11.0-11.6	1.10-1.16	8.9-10.1	712-808	18	1,440	29-31	232-248	300°C / 572°F
SC-3215	11.2-11.8	1.12-1.18	8.9-10.1	712-808	15	1,200	30-32	248-256	300°C / 572°F
*The effective Maximum Operating Temperature for a Samarium Cobalt Magnet is a function of the magnet’s magnetic characteristics and the geometry of the system (the magnet and the circuit). The listing maximum operating temperature is a recommendation and infers and ideal geometry and no external demagnetizing fields. Please engage Dura to review the application before selecting a particular grade.

Reversible Temperature Coefficient for Br (α)
Temperature Range (°C)	Induction Br (α) SmCo 1-5 (%)/°C	Induction Br (α) SmCo 2-17 (%)/°C
-100°C to 20°C	-0.045%	-0.030%
20°C to 100°C	-0.045%	-0.030%
100°C to 200°C	-0.050%	-0.035%
α = Δ Br / Δ T * 100 (Br @ 20°C) [ΔT = Relevant ranges listed above.]

Samarium Cobalt Magnets - Physical Properties
Property	Units	Values SmCo (1-5)	Values SmCo (2-17)
Vickers Hardness	Hv	450 - 500	500 - 600
Density	g/cm3	8.3	8.4
Curie Temp TC	°C	700 - 750	800 - 850
Curie Temp TF	°F	1,292 - 1,382	1,472 - 1,562
Specific Resistance	μΩ⋅cm	53	86
Bending Strength	N/m2	1.8 x 108	1.5 x 108
Compressive Strength	N/m2	10 x 108	8 x 108
Thermal Expansion Parallel (∥) to Orientation (M)	°C-1	6 x 10-6	8 x 10-6
Thermal Expansion Perpendicular (⊥) to Orientation (M)	°C-1	13 x 10-6	11 x 10-6
Young's Modulus	N/m2	1.6 x 1011	1.2 x 1011
Tensile Strength	N/m2	4 x 107	3.5 x 107

The listed values are approximate and should be used as a reference.  Any magnetic or physical characteristics should be substantiated before selecting a magnet material.  Please engage Dura’s magnet Design / Development team members before selecting a design path.
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